To omit the need for the action of foaming a content medium to improve usability, containers filled with shampoo, body soap, hand soap, face cleanser, and so forth are often used with a dispenser that allows the content medium contained in the container to be directly dispensed in the form of foam.
Such a dispenser includes a base cap, which is held by a mouth of the container, and a single cylinder fitted to the base cap. The single cylinder includes coaxially and serially arranged two pistons, i.e., one piston that sucks, pressurizes, and pumps the content medium, and the other piston that sucks, pressurizes, and pumps air. By actuating these pump pistons synchronously by depressing a nozzle head, the content medium and air are sucked, pressurized, and pumped into the corresponding cylinder portions. The content medium and air are mixed together in confluence space located on outlet sides of the pumps and passed through a foaming member such as a mesh. Thus, the content medium is dispensed in the form of foam. (Refer to Patent Literature 1, for example.)
The foaming member is generally assembled to a jet ring (which is called “the foaming member fitting tube” in Patent Literature 1) in advance to facilitate assembly to, for example, a dispenser. The jet ring includes, in a lower part thereof, a small-diameter tubular portion that is suited for being inserted into an upper end portion of a stem.